Southwest Airlines Co. and its subsidiary AirTran Airways have combined more booking systems to make it easier to purchase flights on both.

Dallas-based Southwest on Monday announced customers will soon be able to book flights to any of the combined 97 destinations of the two carriers – including international – in one transaction.

Southwest acquired AirTran in 2010. The carriers last month began offering shared itineraries in five markets. The combined systems will be expanded later this month and both networks should fully connect in April.